% my_member(Element, List) - checks if Element is in List
my_member(Element, Element) :- atomic(Element).
my_member(Element, Compound) :-
    compound(Compound),
    Compound =.. [Head, Tail],
    (Element = Head ; my_member(Element, Tail)).

% my_length(List, Length) - finds the my_length of a list
my_length(Atom, 1) :- atomic(Atom).
my_length(Compound, N) :-
    compound(Compound),
    Compound =.. [_, Tail],
    my_length(Tail, M),
    N is M + 1.